Traditionally, fuel, e.g. gasoline, has been dispensed into automobiles through a nozzle which is loosely inserted in a filling spout for the automobile fuel tank. It is inherent in such an arrangement that fumes from the automotive fuel tank, concentrated with live hydrocarbons, are dispersed into the atmosphere. Such an arrangement was tolerable at certain levels; however, the situation has long existed in which fumes discharged from automobile tanks during refueling are a significant pollutant to the atmosphere.
Contamination of the atmosphere by live hydrocarbons dispersed during refueling operations, as well as a saving of fuel, may be accomplished by transferring gaseous fumes from an automobile fuel tank to a source tank from which the fuel is drawn. That is, as the liquid fuel flows from the source tank into the automobile fuel tank, maintaining pressures involves venting gaseous fumes from the automobile tank to flow into the source tank. Consequently, a balance can be achieved with economy and avoidance of contamination by simply transferring the gaseous fumes from the automobile tank to replace the liquid fuel drawn from the reservoir tank. Of course, such transfer can be accomplished by a variety of techniques including pumps and return lines. However, the gaseous fumes are almost explosive in nature and, of course, are readily compressible in passages which resist free flow. In accordance with the present invention, it is proposed to afford an unobstructed flow passage for the gaseous fumes which is of substantially the same size as the liquid fuel passage and which is unobstructed by irregularities in the passage.
Generally, the provision of equal passages (one for liquid fuel and another for gaseous fumes) of similar size and containing no obstruction, does not present a great problem in view of existing technology. However, other requirements exist which render previously known structures somewhat inapplicable. Specifically, the arrangement of two hoses for dispensing fuel from a fuel pump is particularly troublesome unless the hoses are swivel connected to the rigid members, e.g. the pump and nozzle. Furthermore, in view of the vast number of filling stations which should be equipped with refueling apparatus as considered above, it is apparent that the aggregate cost may assume very large proportions. Consequently, it is important that the couplings involved be simple, economical, durable, and easy to install and assemble.
In general, the present invention relates to a refueling system which incorporates a coupling mechanism for affording a swivel connection between a flexible hose and a rigid member, e.g. a tank or nozzle. Additionally, the coupling provides a uniform passage for fluid flow and furthermore is swiveled to accommodate rotation between the hose and the rigid member. A coupling device incorporates a pair of rigid components, one of which is adapted to be connected to a rigid member while the other is adapted to be connected to a hose. The component connected to the rigid member incorporates a somewhat cylindrical section defining an external concentric, annular groove adjacent to an external cylindrical surface. The hose component telescopically receives the rigid member component in a somewhat cylindrical section defining an internal concentric, annular groove for alignment with the annular groove in the received component. A nylon-like member is then fitted in the aligned grooves to mechanically lock the two components together in rotatable relationship. The external component (hose member) also defines at least one groove for receiving an 0-ring, which O-ring dwells upon the external cylindrical portion of the received component to accomplish a rotatable fluid seal.